Creating Video Transition Presets for Premiere inside of After Effects

I'm looking for a functionality that has been present between Avid <-> Boris Red for a long while now. Create a template inside of Boris Red, save it to quick transitions (equivalent of presets), and it appears as an option when applying a transition, complete with malleable duration of the transition.

Quick internet searching seems to indicate that presets under the Effects listing have to ultimately be compiled in C++ via the SDK (which for many reasons is not an option).

There is also the Essential Graphics holder which is more easily integrated, but I don't really see a way to do A->B transitions within it.